Chapter 7 - "The Slug Club" - In which Harry thinks Malfoy might be a Death Eater, everyone departs for King's Cross, and before getting on the train Harry tells Mr. Weasley his suspicions. On the train, Harry finds he is more famous than ever, but sits with Neville and Luna until Slughorn invites him to tea. After hours of boring conversation, Harry sneaks into the Slytherins' compartment, invisible, and listens to Malfoy brag about working with Voldemort, but when the train stops Malfoy freezes Harry and leaves him behind.
A Very Different Diagon Alley
Weasleys' Wizard Wheezes
Harry and his friends find [Weasleys' Wizard Wheezes] - thanks to a [U-NO-POO] sign - and start to look around the shop.
Following Draco in Knockturn Alley